ClearBlack Display
ClearBlack Display technology, also known as CBD, was introduced at "Nokia World 2010" and the technology has been a headline feature of its recent Lumia models.
ClearBlack display uses a sequence of polarising layers to eliminate reflections.
Polariser layers used in display solutions are bit more sophisticated than in sunglasses. Light rays actually get “processed” many times on its way in and out of your phones´s screen.
There’s both a linear polariser and retardation layers between the surface of your phone and the display. When light hits your screen, this is what happens:
ClearBlack display uses a sequence of polarising layers to eliminate reflections.
Polariser layers used in display solutions are bit more sophisticated than in sunglasses. Light rays actually get “processed” many times on its way in and out of your phones´s screen.
There’s both a linear polariser and retardation layers between the surface of your phone and the display. When light hits your screen, this is what happens:
- It hits the linear polariser, this vertically polarises the light. (Polarising means – roughly – aligning the wave vibration in a particular direction).
- Then it hits the circular polariser retardation layer. This converts the light again, making it right-circularly polarised.
- Then it hits the screen and bounces off it, switching the rotation of the light to leftsite.
- It goes back through the retardation layer. When this happens, the light becomes horizontally polarised.
- Finally it hits the linear polariser, since the light is horizontally polarised at this point it is blocked entirely by this optical solution.
The light produced from the display itself, having not passed through a polarizing filter, is able to escape without being affected.